We pointed out that the Regent was quite an adult venue for someone just crossing the threshhold into her 30s, and she agreed: "I am so classy! Classy with a K, but classy. I'm almost there with the C."

Jokes aside, Richie opened up about her journey from reality-show wild child to married mother of two.

"If life was about one lesson, we'd all be perfect. But it's not," she said. "I try to learn lessons every day. Life is about waking up and going out there and being the best version of you."

Her morning and afternoon were spent with daughter Harlow, 3, and son Sparrow, who celebrated his second birthday Sept. 9.

"Their life doesn't stop when it's my birthday. They have school and ballet and this and that. I was just a mom, which I'm totally happy being," she said, "My son just had his birthday, and they just don't care. They're birthdayed out! We just had the cake and the song and the whole bit."

Richie did enjoy some tiny spoils, however, such as a tiered birthday cake with gold detail, a dance-off in the suite led by emcee Ronson and the obligatory playing of her dad's hit "All Night Long."

A video montage was projected starring her kids and close ones, and the Winter Kate designer did land one exclusive gift — the unreleased Samsung Galaxy SII, which she used to snap pics of her guests throughout the evening.

"I'm so excited about this new chapter in my life and so ready for something new," Richie said. "So many of my girlfriends say that your 30s are the best. I couldn't be more ready."